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New One-Way Line for Electric Transmission System 被引量:3
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作者 Michael Bank 《Journal of Energy and Power Engineering》 2012年第8期1320-1327,共8页
There are three well known types of wire lines for transmitting electrical energy or information. The first type is ordinary two wires line (below A-Line). The second type is so-called single-wire line, where ground... There are three well known types of wire lines for transmitting electrical energy or information. The first type is ordinary two wires line (below A-Line). The second type is so-called single-wire line, where ground plays the role instead of second wire. Polyphase systems belong to the third type, three phase system is the most popular among them. The purpose of this article is another attempt to build a one-wired (without ground) system--the transmission of electrical energy. In this paper an original idea of building such a system is justified, the results of simulations and laboratory modeling are presented. It is shown that the proposed method can reduce the cost of electric transmission lines, the losses in them and significantly reduce interferences. 展开更多
关键词 electrical lines three phase system one line system TRANSFORMER delay line.
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General Analytic Solution of the Telegrapher’s Equations and the Resulting Consequences for Electrically Short Transmission Lines 被引量:1
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作者 Steffen Kü hn 《Journal of Electromagnetic Analysis and Applications》 2020年第6期71-87,共17页
Based on classical circuit theory, this article develops a general analytic solution of the telegrapher’s equations, in which the length of the cable is explicitly contained as a freely adjustable parameter. For this... Based on classical circuit theory, this article develops a general analytic solution of the telegrapher’s equations, in which the length of the cable is explicitly contained as a freely adjustable parameter. For this reason, the solution is also applicable to electrically short cables. Such a model has become indispensable because a few months ago, it was experimentally shown that voltage fluctuations in ordinary but electrically short copper lines move at signal velocities that are significantly higher than the speed of light in a vacuum. This finding contradicts the statements of the special theory of relativity but not, as is shown here, the fundamental principles of electrical engineering. Based on the general transfer function of a transmission line, the article shows mathematically that an unterminated, electrically short cable has the characteristics of an ideal delay element, meaning that an input signal appears at the output with a slight delay but remains otherwise unchanged. Even for conventional cables, the time constants can be so small that the corresponding signal velocities can significantly exceed the speed of light in a vacuum. The article also analyses the technical means with which this effect can be conveyed to very long cables. 展开更多
关键词 Telegrapher’s Equations Transmission line Theory Special Theory of Relativity electrically Short Transmission lines FTL Communication
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Dependence of the emission electric dipole line strength of Eu^(3+) on the composition of lead borate glasses
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作者 江莎 刘子怡 +1 位作者 夹国华 段昌奎 《Journal of Rare Earths》 SCIE EI CAS CSCD 2009年第6期915-918,共4页
Lead borate glasses xB2O3+(99–x)PbO+0.5Eu2O3(x=70,60,...,10) were prepared by melt-quenching method.The luminescent properties were characterized with excitation and emission spectra.The emission intensities for 5D0-... Lead borate glasses xB2O3+(99–x)PbO+0.5Eu2O3(x=70,60,...,10) were prepared by melt-quenching method.The luminescent properties were characterized with excitation and emission spectra.The emission intensities for 5D0-7FJ(J=0–4) were analyzed to give variation of the relative electric dipole line strengths with the composition of glasses so as to examine the crucial implicit assumption of independent electric dipole line strength on the composition of glass in the Phys.Rev.Lett.2003,91,203903 paper studying l... 展开更多
关键词 electric dipole line strength Eu3+ lead borate glasses local field effect rare earths
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An Exact Solution of Telegraph Equations for Voltage Monitoring of Electrical Transmission Line
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作者 Daouda Konane Wend Yam Serge Boris Ouedraogo +3 位作者 Toussaint Tilado Guingane Abdoulaye Zongo Zacharie Koalaga François Zougmoré 《Energy and Power Engineering》 CAS 2022年第11期669-679,共11页
Telegraph equations are derived from the equations of transmission line theory. They describe the relationships between the currents and voltages on a portion of an electric line as a function of the linear constants ... Telegraph equations are derived from the equations of transmission line theory. They describe the relationships between the currents and voltages on a portion of an electric line as a function of the linear constants of the conductor (resistance, conductance, inductance, capacitance). Their resolution makes it possible to determine the variation of the current and the voltage as a function of time at each point of the line. By adopting a general sinusoidal form, we propose a new exact solution to the telegraphers’ partial differential equations. Different simulations have been carried out considering the parameter of the 12/20 (24) kV Medium Voltage Cable NF C 33,220. The curves of the obtained solution better fit the real voltage curves observed in the electrical networks in operation. 展开更多
关键词 Telegraph Equation electric Network Voltage Variation electrical Transmission lines Analytical Solution
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Closed form soliton solutions of three nonlinear fractional models through proposed improved Kudryashov method
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作者 Zillur Rahman M Zulfikar Ali Harun-Or Roshid 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第5期192-205,共14页
We introduce a new integral scheme namely improved Kudryashov method for solving any nonlinear fractional differential model.Specifically,we apply the approach to the nonlinear space-time fractional model leading the ... We introduce a new integral scheme namely improved Kudryashov method for solving any nonlinear fractional differential model.Specifically,we apply the approach to the nonlinear space-time fractional model leading the wave to spread in electrical transmission lines(s-tfETL),the time fractional complex Schrödinger(tfcS),and the space-time M-fractional Schrödinger-Hirota(s-tM-fSH)models to verify the effectiveness of the proposed approach.The implementing of the introduced new technique based on the models provides us with periodic envelope,exponentially changeable soliton envelope,rational rogue wave,periodic rogue wave,combo periodic-soliton,and combo rational-soliton solutions,which are much interesting phenomena in nonlinear sciences.Thus the results disclose that the proposed technique is very effective and straight-forward,and such solutions of the models are much more fruitful than those from the generalized Kudryashov and the modified Kudryashov methods. 展开更多
关键词 improved Kudryashov method fractional electrical transmission line equation fractional nonlinear complex Schrödinger equation M-fractional Schrödinger-Hirota(s-tM-fSH)
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Reducing Greenhouse Gas Emissions through Improving the Life Span of Wooden Power Electric Poles of Eucalyptus saligna
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作者 Joseph Voufo Zakari Yaou +3 位作者 Florent Biyeme Rolland Djomi Richard Dadji Metangmo Théodore Tchotang 《Modern Mechanical Engineering》 2022年第1期1-26,共26页
The present work deals with reducing greenhouse gas emissions through improving the life span of wooden power electric poles of Eucalyptus saligna. Indeed, in Sub-Saharan African countries, Cameroon in particular, mos... The present work deals with reducing greenhouse gas emissions through improving the life span of wooden power electric poles of Eucalyptus saligna. Indeed, in Sub-Saharan African countries, Cameroon in particular, most of the power line networks are made of wooden supports and according to the Cameroon energy distribution company, wooden poles represent 32% of the causes of death linked to the state of the network. The company’s 2019 annual report indicates that 40,000 wooden poles were in critical condition and should be replaced. A significant number of mechanical failures affecting these supports have been observed. For example, on the HVA/LV power line “D17 Nko- abang” in Yaoundé in Cameroon, less than three years old, 10 (ten) cases of poles falling and/or breaking, due to their mechanical loading, were observed over a period of fewer than nine months, causing an average service stoppage for more than 11 hours and affecting an average of 3280 customers. These incidents lead to questions about how the supports are dimensioned and what load capacities they are designed to support. The aim of this work is, therefore, to suggest a method of dimensioning wooden poles hence reducing green- house gas emissions due to the deforestation by reducing the number of woo- den poles at risk to be replaced on Cameroon’s electricity distribution network. And more specifically, to reduce the number of mechanical failures affecting the wooden supports observed by analyzing the current wooden supports with their loads and to make proposals for improving the actual dimensioning me- thods. From the study carried out, it appears that 449 out of 845 supports, i.e., 53% needed to be replaced or monitored because they support the nominal forces ranging from 85% to 150% of their admissible limit and proposals have been made to improve their dimensioning. 展开更多
关键词 electrical Power line Dimensioning Wooden Pole Efforts on Pole Pole’s Height Method of Loading Overload Coefficients
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Two Independent Numerical Studies Demonstrating How to Efficiently Eliminate Electrolysis Side Reactions in Magneto-Hydro-Dynamic Pumping System
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作者 Adam Bouras Raoudha Chaabane Kamel Charrada Rachid Sald 《Journal of Chemistry and Chemical Engineering》 2012年第6期536-546,共11页
In this work, a numerical study for designing a new kind of MHD (Magneto-Hydrn-Dynamic) pumps is presented. This technique makes a compromise between electrolysis prevention and high flow rate performance. This tech... In this work, a numerical study for designing a new kind of MHD (Magneto-Hydrn-Dynamic) pumps is presented. This technique makes a compromise between electrolysis prevention and high flow rate performance. This technique should eliminate electrolytic bubble generation, electrodes wear and fluid propriety modification. All these side phenomena are prevented by considering isolated electrodes. The numerical presented results in this paper demonstrate that continuous MHD pumping is possible with isolated electrodes. The MHD excitation combines a high frequency altering current with a low frequency altering magnetic field. In order to validate our results, two independent theoretical methods for computing flow rate are followed. The two presented independent approaches show that high flow rate is possible even with isolated electrodes. To overcome the problem of dimensioning this kind of pumps, a generic numerical analysis is proposed. Hence, the pump performances as functions of the external parameter are studied and tools to calculate for a given fluid and the optimal high frequency regime are provided. 展开更多
关键词 Magneto-Hydro-Dynamic iorenz force high frequency regime electric line model characteristic impedance high flow rate.
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The double auxiliary equations method and its application to space-time fractional nonlinear equations
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作者 L.A.Alhakim A.A.Moussa 《Journal of Ocean Engineering and Science》 SCIE 2019年第1期7-13,共7页
This paper reflects the execution of a reliable technique which we proposed as a new method called the double auxiliary equations method for constructing new traveling wave solutions of nonlinear fractional differenti... This paper reflects the execution of a reliable technique which we proposed as a new method called the double auxiliary equations method for constructing new traveling wave solutions of nonlinear fractional differential equation.The proposed scheme has been successfully applied on two very important evolution equations,the space-time fractional differential equation governing wave propagation in low-pass electrical transmission lines equation and the time fractional Burger’s equation.The obtained results show that the proposed method is more powerful,promising and convenient for solving nonlinear fractional differential equations(NFPDEs).To our knowledge,the solutions obtained by the proposed method have not been reported in former literature. 展开更多
关键词 Double auxiliary equations method Fractional partial differential equation Exact solution Traveling wave solution Nonlinear low-pass electrical Transmission lines Fractional Burger’s equation.
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